Six separate projects related to outcomes of patients with rheumatic diseases are included in this report. The first project, ?Genetic determinants of ankylosing spondylitis severity,? is a prospective observational study of 600 subjects with ankylosing spondylitis (AS) that seeks to identify genetic determinants of ankylosing spondylitis severity. The severity of AS varies widely among patients, but the reasons for this variation are unknown. Because the susceptibility to AS is largely genetically determined, it is possible that the severity of AS may also be largely genetically determined. This project will test genotype-phenotype correlations in a large sample, stratified by duration of AS to capture inflammatory signs in early duration subjects and the degree of fusion and functional impairment in late duration subjects. Over 500 subjects have been enrolled, and genetic testing and data analysis has begun. Initial clinical predictors of functional and radiographic severity have been identified. Collaborators include Drs. J. Reveille, M. Weisman, and J Davis. The second project, ?Progression of spinal fusion in ankylosing spondylitis,? is a feasibility study with a goal to develop and test a measure of spinal fusion in AS based on quantification of calcification of the lumbar intervertebral discs by computed tomography. Subject enrollment is in progress. The collaborators on this project are Drs. J. Flynn and L. Yao. The third project, ?Clinically important changes in rheumatoid arthritis,? is a prospective observational study of clinically important changes in rheumatoid arthritis (RA) activity. Current criteria for improvement in RA have not emphasized the patients? perspective. It is also not known if patients rate changes in their symptoms and signs of RA similarly as their physicians, or if different patients are concordant in their judgments of how much of an improvement in symptoms represents an important improvement. The goals of this project are to identify benchmarks of important improvement in pain, functioning, and global arthritis status in RA based on the self-assessment by patients of changes in their symptoms. A secondary goal is to examine the measurement properties of preference measures. To date, 150 patients have been assessed before and after escalation of their anti-rheumatic treatment. The fourth project, ?Measurement of functioning in rheumatoid arthritis,? uses secondary analysis of clinical trial data to deconstruct measures of functional limitation into reversible components related to active synovitis and irreversible components related to joint damage. Data analysis is completed, and has indicated that reversibility of Health Assessment Questionnaire Disability Index in RA decreases with the duration of RA and with increasing radiographic damage. This project has suggested several additional areas of inquiry. The fifth project, ?Malignancy in patients with rheumatoid arthritis,? uses the Medicare-SEER database to compare the incidence and survival from cancer between patients with RA and those without RA. Rheumatoid arthritis may modify the risk of malignancy, increasing the risk of certain types of cancer (lymphoma, lung) and decreasing the risk of other types of cancer (colorectal). However, risks of malignancy are not well defined in patients with RA, nor is it known if the outcomes of cancer are similar between patients with RA and those without RA. The Medicare-SEER database is a large population-based linked database that combines clinical information from Medicare billing records with cancer data from SEER locations. SEER is the nation?s primary cancer epidemiology program, operated by the National Cancer Institute. Patients with RA are identified from Medicare records, while cancer incidence is obtained from SEER. Data abstraction is currently underway. The goals of the sixth project, ?Clinical epidemiology of systemic lupus erythematosus,? are to better estimate the prevalence of systemic lupus erythematosus (SLE), to investigate the outcomes of cardiovascular disease among patients with SLE, and to identify clinical features and health care practices that are associated with mortality. This project uses a recently validated method that combines administrative data and clinical data to estimate the prevalence of SLE, which is currently imprecisely known. These administrative data have been used to identify structural characteristics of health care associated with the risks of in-hospital mortality in patients with SLE, most notably the SLE-related experience of the attending physician. Recent work suggests that similar associations exist among patients transferred between hospitals, which has implications for patient management.